Thought Collision Factories is a collection of Oppenheim’s work tracking his sculptural development over 14 years between 1972 and 1986. His endeavour throughout his working life was to make ideas material. Currently exhibited at Henry Moore Institute, the visitor finds a variety of this work in a broad range of titled media. Common to all is the intention that the very nature of ideas, chimeras, notions, thinking, is translated metaphorically into matter. The viewer frequently finds, therefore, that Oppenheim’s sculptural events take place through time. Many such events are ephemeral and have warranted an extra level of abstraction in order to be recorded. As works in themselves these speak of well-wrought but graceful precision. Where the nature of ideas is captured with temporal and ephemeral limitations, the recorded abstractions of these suggest the importance of memory.

Strongly imparted through the work is the imperfect and flawed nature of thought and meditation. This impression is particularly resonant in two large-scale works, which dominate their respective spaces at Henry Moore Institute. Both are elaborate, aesthetically balanced ‘machines’ with no discernible practical function. These machines vibrate and operate as factories that produce processes rather than products. Vibrating Forest (From the Fireworks Series) (1982) incorporates steel, aluminium track, cast plaster, a lamp, a candyfloss machine, vibrating motors and fireworks. Landing Structure #3: An Armature for Projection consists of aluminium and steel, iron, wood, copper, Pyrex glass, electric motors and, again fireworks. Both machines are spectacular while remaining modest for their lack of practical application. Oppenheim described the machine as ‘a rather perfect device to use as a metaphor for thinking’. Machines can always malfunction and break down. They are imperfect. Here the machines visualise the production of ideas.

During the course of this exhibition three signs consisting of words spelled out with fireworks will be ignited in front of the Henry Moore Institute building. The titles spelled out are ‘NarrowMind’, ‘Mindless Less Mind’ and ‘Mind Twist’. These works are from 1975. The process of thought is echoed in the ephemeral and temporal nature of the works once ignited. While the temporary nature of mental process is examined in this way, the particular titular ideas examined are made strongly material as a banquet for the senses. The material process of these works involves sight, sound and smell. The fireworks and flares incorporated into these exhibits are at their most material when they dematerialise. Photographs of previous works of exactly similar conceit can be found at Henry Moore Institute.

From the early 1970s the visitor finds wall-mounted works consisting of aerial photographs of large-scale ephemeral works with maps of the territory in which they took place. Oppenheim uses the scale of his own body and that of the landscape to expand the definition of sculpture here. Poison (1977) consists of six aerial photographs taken from different angles of the word ‘Poison’ spelled out luminously. The map of the territory can be found alongside. It is a map charting part of Minnesota, near Minneapolis. A similar work from 1972 titled Polarities can be found. Particularly striking and somewhat irksome is a work of similar conceit titled Whirlpool – Eye of the Storm (1973). A spiralling vapour trail from an aeroplane is captured from both ground level and other aerial angles here.

Thought Collision Factories examines Oppenheim’s quest to make ideas material. The nature of ideas is frequently echoed. At first glance it is counter intuitive to make ideas and thought processes material in these ways because of our commonly held sense of mind-matter duality. However, further reflection takes into consideration the ubiquity of computers, the internet, social media and artificial intelligence. This is not directly invoked by the exhibition however. It is a challenging collection that succeeds in demonstrating Oppenheim’s expansion of the nature of sculpture and inspires further reflection.